Automatic farming system



June l, 1965 1 D. BARRY AUTOMATIC FARMING SYSTEM 8 Sheets-Sheet 1 Filed May 6, 1959 NY 9v mh fR.

INVENTOR.

June l, 1965 L. lD. BARRY 3,186,493

AUTOMATIC FARMING SYSTEM Filed May 6, 1959 8 Sheets-Sheet 2 MQW `lune l, 1965 l... D. BARRY AUTOMATIC FARMING SYSTEM 8 Sheets-Sheet 3 Filed May 6, 1959 INVENTOR.

June l, 1965 L. D. BARRY 3,186,493

AUTOMATIC FARMING SYSTEM Filed May 6, 1959 8 Sheyets-Sheet 4 fag. /2

- 30a AWAY/AWA' ./l' 9; INVENToR.

June l, 1965 l.. D. BARRY 3,186,493

AUTOMATIC FARMING SYSTEM Filed May 6, 1959 8 Sheets-Sheet 5 IN V EN TOR.

June l, 1965 L. D. BARRY 3,186,493

AUTOMATIC FARMING SYSTEM Filed May 6, 1959 8 Sheets-Sheet 6 IN V EN TOR.

June l, 1965 L. D. BARRY 3,186,493 Lg AUTOMATIC FARMING SYSTEM Filed May 6, 1959 8 Sheets-Sheet 7 IIIIIIIII-y mfr 662 IN VEN TOR.

June l, 1965 l.. D. BARRY AUTOMATIC FARMING SYSTEM Filed May e, 1959 8 Sheets-Sheet 8 INVENTOR.

3,186,495v AUTMATIC FARMING SYSTEM Leonard D. Barry, 193% Pennington Drive, Detroit, Mich. Filed May 6, 1959, Ser. No. $111,500 22 Claims. (Cl. 17E- 26) This invention relates to farming systems and devices and in particular to novel means whereby farming `implements can be automatically propelled, guided, and controlled while tilling or otherwise functioning on the land. y

An object of this invention is to provide a practical and novel system and devices for automaticallytilling a field.

Another object is to provide novel means to automatically guide a device in a succession of rows across or along a field.

Another object is to provide a tilling device that automatically moves back and forth between limits of travel and indexes to follow a parallel path selectably at one or both limits of travel for respectively use with one and two-way implements.

A further object is to provide novel means on` the til-ling device for lifting, lowering, and holding implements level and in particular for backing out and controlling the depthl and angle of a plow bottom whereby plowing can beautomatically accomplished. t

A further object is to provide a tiller which not only is steered automatically on a eld, but one which can be manually steered for operation to operating position or on roads, and further to provide a tractor which can be either manually or automatically steered according to the type of work being done to enable the tiller to do all the jobs of a farm tractor as well as automatic cultivation. i It is anobject to provide novel guide and steering ar-v rangements and control means to reverse the tiller without reversing the direction of rotationof its drive toenable utilization of a simple drive andto simplify steering re quirements for automatic operation. u It is therefore an object to provide separate implement lifts for right and left hand implements and for the lowering of one implement lift only when the vehicle operates in one `direction 3,186,493 Patented .lune l, 1965 "ice,

lto the ground. As a feature of the controls the bridge is i controlled as set up by the operator to index when the car reaches either or both ends of the bridge or for tilling in cross-rows, is set up to movercontinuously with the car stationary with respect to the bridge until an index control l located on the ground causes the car to index along the bridge. As a further feature the implements are automatically lifted while the bridge is indexed with the car at the end of the bridge, while the bridge is moving from one run to another or on aturn-around, Whenever the bridge is not spanning a run across the field, and when the direction of an implement is not proper for the direction of travel of the car or the bridge that implement is automatically held lifted provided the operator properly sets up the tiller for operation.

Other and further features and objects of this invention will be apparent to those skilled in the art upon consideration of the specific embodiments described hereinafter and illustrated in the accompanying drawings wherein:

FIGURE 1 is a planV view of the bridge form of the tiller shown on `a'guide track. l

FIGURE 2 is a side view of the tiller shown in FIG- UREl.

and the lowering of the other `implement lift only when the tiller operates in the reverse direction during tilling and to hold the implements out of the ground while the `tiller is indexing and moving to working position.

One embodiment of this invention utilizes a bridge type structure to carry and guide an implement car back and forth thereon. With such a structure it is an object-to support the bridge at its ends on swivel casters whereby it can `be moved endwise to span dierent `runs across the eld and moved to and from the field easily. It is another object to support the bridge on pivoted trucks whereby it is pivoted from one run to another without requiring that the implements be reversed orlifted.

Another object is to provide a farming device having "FIGURE 3 is a partial end view of the tiller shown in FIGURE l drawn to a larger scale than FIGURES l and 2.and showing the side of a caster truck supporting the bridge` i FIGURE 4 is an end View of the truck shown in FIG- URE 3 with aportion of the bridge. n

FIGURE 5 is a plan view of the implement car and its drive.

FIGURE 6 is a side'view of the car and drive with` implements in place.

FIGURE 7 is an end view ofthe car and implements.

`FIGURE 8 is a track layout Vfor the tiller. i

FIGURE 9 is a track switch Adetail enlarged from area 9 circled in FIGURE 8.

FIGURE 10 is aperspective view` of a turning switch in the track. Y

FIGURE 11 is a schematic diagram of controls for the tiller shown in the preceding views. y

FIGURES 12 and 13 are perspective views of two variations ofthe tiller and track layout.

FIGURE 14 is a diagrammatic view of the drive for the tillers shown in FIGURES l2 and 13. i

FIGURE 15 is a perspective view of a two-span bridge tiller.

FIGURE 16 is a perspective View of the hinge details between the bridge sections shown in FIGURE l5.

FIGURE 17 is a schematic `control diagram of the controls for lowering the implements alternately for longitudinal operation.

FIGURE 18 is aV perspective view of onev of the row locators spaced along the bridge to stop the car.

FIGURE 19 is a diagrammaticperspective View of a cable-guided tiller. Y

Y FIGURE 20 is a perspective view of a telescopingframe-guided tiller.

VGo

The rst form of this invention to be described brieily comprises a bridge structure supported on rails by swivel powered casters at the ends of the bridge, a car arranged `to move back and forth across the bridge, and means on the car for supporting an implement in operable relation of caster movements;`

FIGURE 21 is a schematic diagram of controls for the tillers shown in FIGURES 19 and 20. Y

FIGURE `22 is adiagrammatic perspective View of a light-beam-guidedV til-ler.

FIGURE 23 is a Vsequence diagram illustrating the cycle FIGURE 24 is a schematic diagram of the controls fo thetiller shown in FIGURE 22.

FIGURE 25 is a schematic diagram of a variation of a portion of FIGURE 24. 'V

FIGURE 26 is a side elevation of the tiller of FIG.- URE 22.

A FIGURE 27 is a front elevation of a portion of the tiller shown in FIGURE 26.

steering arrangement forcombining manual and auto-v matic steering.`

FIGURE 30 is a perspective sectional Vview of a special check valve in the steering control of FIGURE .24.

FIGURE' 31 .isa schematic plan view of a field with a Y tiller car and control truck with light beams shown for guiding the' same.

Referring'to the `drawings and in particular to FIG- URES 1, 2.,V 3, and 4; a bridge tiller 28 has a frame or bridge span 30 supported on trucks 32 and 34 to run on parallel rails 36 and 38 respectively. Truck 34 is rigidly bolted to the bridge with bolts 4t) whereby it can be adjusted to the track gage or replaced by another truck. Truck 32 lis hingedto bridge 3ft on pivots 42 to compensate for variation in track gage and held vertical Iby spring stops 43 which limit the movement of truck 32 on pivots 42. Each truck is supported on and driven through two pivoted wheel assemblies or swivel casters 4d each having a thrust bearing 66 for supporting the truck. The wheel 46 of each caster 44 is driven by endless cable 48 wrapped around four. cable drums 49 each secured'on a vertical shaft Sil-secured in bearings 54- to the frame of the truck. A collar 60 supports each shaft 59 on a bear-` ing 54. A Each shaft 50 extends down into a caster 44 on the swivel axis of the caster. The hub of a beveled gear 68 secured to the bottom of shaft 50 and supporting a radial and thrust bearing 7) against the underside of the caster together with collar 60 holds the caster to the truck frame; Beveled gear 72 meshing beveled gear 63 and secured on shaft 74 bearing in the caster Iframe parallel wit,h the shaft 76 on which wheel d6 revolves 4drives sprocket 77 secured onshaft Mwhich in Vturn drives sprocket 78 on wheel 46 through chain 80. The caste-r driveshown in FIGURE 2,7 is equally applicable.

.Wheels i6 preferably are equipped with rubber tiresSZ having a groove 84 which fits over the angle rail 36 or 11S.v The rubber tireV is recessed so that the center of the groove does not bear on the rail. Webs 85 prevent the tire from excessive spreading. The tread sides Aof the groove 84 forms an angle less than 90 degrees to make good contact when under load on the 90 degree structural angle rail and provide good traction. The tires can be changed easily if Ynecessary by removing bolts S6 which secure disk $7 against the outer side of the tire and wheel, shaft 76 being securely held in hole 33 on'only one side of the swivel base 90.

Eachv caster has a sprocket tooth rack 92. wrapped around the base of the wheel support bracket 9i) and secured thereto or cast as a part thereof. A chain 94 around thev sprockets 92 join in alignment the two swivel brackets 90 on each end of the tiller so that the casters on each truck will turnV together with their wheels in the same direction.

It may be desirable to connect the casters on opposite ends of the tiller 'to swivel together depending on how the casters are guided. VIf a full track is provided as shown the 'connection is not needed unless used to throw switches along the trackway. To provide this connection a sprocket 97 meshes chain 94 on each end, the sprockets 97 on eachend arefturned together by movement of either through beveled gears and shaftingtir and including flexible .shafting 99 to connect to thehinged truck as shown. `By adding control over steering as illustrated in FIG- URES 24 and 29 for example the bridge tiller can operate vfor a straight run .and index and make a second run without rails as guides. If the tiller-of FIGURE 24 were the bridge, the implement car would travel lback and 'forth at right angles to 'the direction of the arrow between indexing movements of the bridge in the direction of the arrow.

Within bridge 3i) a second frame lltltl resiliently supports -a motor or en-gine 192 complete with its cooling,

i lubricating, fuel, and electricalV systems. A' governor 103 controls the speed of the engine. Frame 160 is supported from bridge Si? near the ends thereof by rods 104 secured or hooked to 'the frame and bridge preferably with resilientwashers or springs 1% thereon to cushion vibrations still further. The inner frame is likewise held from lengthwise and crosswise movement to the bridge. Frame 1% lalso supports `fuel tank 163, caster drive cable drum 11b, speed reducer 112, the engine transmission 114, a track comprising channel rails or guides 1116 and 11S with farm implement car or carrier 12? therebetween, car

control linkage 122, implement lift control linkage 124, and power takeoff 126 and `shafting 127 which drives speed reducer 123 "located on truck 34 through universal joint 12g. Y I

A cable drivedrum 13d `for supplying power to car is continuously driven in one direction by engine 1112 through speed reducer 128 during operation of the tiller.

' About drurn 13rtt is wrapped a few turns of an endless drive cable 132 which extends to the opposite track 32 and is tensioned and directed back along the desired line of travel by sheaves 134.

lFIGURES 5, 6, and 7 are referred to for details of car 12d and its endlesscable drive. Cable drumsld and 137 normally `free to revolve and have axial movement von -vertical shaft 1318, which is secured to car 120, have the desired number of turns of different sides of the cable 132 wrapped thereon in the sameY direction whereby the cable turns the drums in the 'same direction. The cable leaves'drive drum 136B, wraps rst around drum 136, then on to direction changing pulleys 134 and back to and around drum 137 and on to the drive drum Iil.

The facing flanges of'drums 136 and 137 have beveled gears ldtland 141 securedrespectively thereto which errgage under the force of springs 142 and 143 with beveled gears .144 and 145 respectively, Beveled gears 144i .and 145 are connected through reverse gears 146 and 14'/ so that either or both beveled gears 1de and 145 drive hydraulic pump 143 located on the car. The opposite flanges of drums 13o and 137 havesecured thereto clutch faces 15d and 151 respectively which engage respectively clutch plates 152 and 153 mounted in line with the line of pull of the cable on the frame of car 12@ to lock either drum Ito the frame without horizontal torque on the cable drums 136 and 11W-when either is engaged with the frame. The clutch of either drum 136 or V'137 is caused to engage its clutch plate to stop the cable side relative to the ca'r and thereby move the car `along the bridge ina direction depending on which cable drum is engaged with the car frame through its locking clutch. To insure that only one drum is locked `at a time lock yoke 154, provided with two wheels ywhich roll on the facing flanges of cable drums 1136 and 137, is pivoted at 153-6 on an axis in the plane of the Hangs faces, and the other end of this yoke lever is provided with two wheels-15? and 153 each on a forked branch of-yoke 154 held outward of adjacent sides lof the cam frame for rotation parallel to the plane of the side that they extend beyond. Hydraulic cylinder 16@ is connected -to act'uate yoke 154 to force the wheel 15S, whichV turns in a plane lengthwise the bridge, to engage either the 'lower rail 162. or the upper rail-163 of linkage 122, in FIGURE 1l. Thus cylinder and linkage 122 control the position of yoke 154 `which rengages either or neither drum with the frame according to the vertical position of wheel 15S."

As seen in plan view, FIG. 5, the car yhas a square frame 164 of channel-iron. Eight wheels 1F66 are mounted two on each side to run between the channel rails 116 and 118 lengthwise the bridge. Both sets of opposite car wheels 166 t in andbetween channels '116 and 118 whereby transverse plowing (al-ong the length lof the bridg?, i.e.fron1 rail to rail) orV longitudinal plowing (parallel to the rails) can be achieved according to which Way the car is turned before inserting it between the channels. A section of channel 132, FIGURE 2, is bolted in place whereby the `car can be removed from thechannelrails, turned 9.0 or 270 degrees, and inserted back between the channels. For this reason the car `is provided with a square frame and wheels on all sides, otherwise the implement would need to be unfastened yand turned or a turntable provided on the car for the` implement lift. Eight implement supporting brackets 163 are bolted to and extend'below the frame., An implement frame or beam 17@ is supported on four parallel bars 172 each pivot-ally joined at oneend to the implement frame and at the other end each toa bracket 163 and arranged to enable parallelogram movement. Piston cylinder 174 (FIGURES 6 and 7) is linkedlto shaft 176 connected between two adjacent bars 172 whereby the implement 178 is lifted from the ground. The parallelogram move- `ment insures that an implement, such as` the left-hand plow shown complete with colter, is maintained parallel with the land .and enables easy lifting of the plow by a backward swing of the parallelogram lift. Land wheel 130 is adjustable to suitably Vgage `and limit the `vertical position of the implement. A reverse implement 178', in this case a right-hand plow, is mounted for the reverse travel of the car. When either implementis lifted as to be lifted from the groundand the other implement lowered within a minimum "space and `travel of the car.

The lines of pull of cable 132 -as described bythe diam-` eter of drums V136 and 137 and arrangement of cable 132 j g are in line vertically with the center' of pull of the im- `and D, FIGURE 8, should be lengthwise the eldfor minimum track cost. The track, which is similar to industrial caster tracks in many respects, is supported on concrete footings or piers 182 by bent rods 183 welded "to the underside of the rails, see FIGURE 10Q The bridge travels along run A, crosses to run B on narrow gage at the top of the View, runs downB to the bottom, crosses to run C, and runs up and down D to turnaround caster guide loops 184 and hits'indeX-stop control 186 mounted in the ground. When the bridge hits an indexstop control with the car .at either extreme end of the bridge the ignition circuit of the engine is opened as will hereinafter be described with FIGURE l1, theindication being. that transverse or longitudinal operation is cornpleted. `lf the car is not at the end of the bridge the bridge continues back and forth between end turnaround loops 133 at the entry to the iield and turnaround loops 134 at the end ofthe line until the car reaches the end of the bridge stopping the bridge at the next index-stop control reached. Note that the crossover curves extend into the field.

A detail of the switches circled in FIGURE 8 is shown `in FIGURE 9. Two-Way throw switch 190 is operated by movement of the casters, byihand or by any suitable means, and the three-way switch 191 is stationary. Throw switch 19t) consists, of stationary plates 192, 193, and 194. Plates 193 and 194 support curves-195 and 1% pivotally on countersunk rivets 197 at the tangent points to the narrow gage runs. The opposite ends of the curves 195 and 196 .are pivotallyattached by pin and slot to shifting plate 19S which Vrests within a recess on plate 192. Stationary switch 191 consists of a plateZtiO to which tapered ends of the various converging rails are welded being arranged to properly pickup the casters.` yUpright flanges 2112 welded to plate 2130 aid in guiding the casters about `the curves. 'i

In operation the first truck caster the bottom of FIGURE 9 passes stationary switch 191 without turning olf, since the following caster is connected by chain 94 to swivel therewith; When the first caster 1s implement 173 its implementframe or beam 170' is` within the length of the car thereby enabling theicar to` i approach close tothe trucks 32 and 34 andthe implement proper design of-the switches.

tionary switches should provide enough space for the,V

turns left on curve 195 the following caster is on the middle of switch 121, and by the action of the first caster is turned on to curve 203. The other castersV on the other truck `following the opposite rail follow the same pattern and thecr-osswise movement of the bridge is changed to lengthwise movement. The tiller entering the field from the barn 266 turns from narrow gage to wide gage land as long as it operates stays within the field. With the tillcr at the'turnaround loops 188 the operator can direct the casters back to the narrow gage or one of Athe turnaround switches can be solenoid or hand operated. lf one caster is properly directed any others connected to be turned therewith will follow properly with The middle of the staf casters to establish their proper direction before engagapproaching from ing with the angle rail again.

The turnaroundsare designed with a slight drop for thecaster to drop to the switch center after completing the turn as seen in'FGURE l0. Upon approaching the turnaround switch 210 Iall casters follow straight, since they prefer the level track to switching olf and up an abrupt ledge 211. Upon following the turnaround curve V212 each caster drops to a switch center plate 214 and follows up the line 216 having completed a 180 degree turnaround ofthe casters. `Plate 214 .as well as other stationary switch plates are curved down on the ends of the switch meeting the caster wheels.`

It should be observed that the bridge does not change itsA direction anywhere on the track layout within field D but turns on curves such Ias curve 22d. Further, since the bridge does not turn around at the ends of runs A,

B, C, and D, many implements when operated longitudinally must be reversed, changed, or used alternately for successive runs when the bridge is moved from runs A to B, `B to C, C to D, D to D return, D to C, etc.

There ,are two hydraulic control systemsgone on the car and one on the bridge. The implement lift cylinders and the lock yoke cylinder are controlled by a hydraulic system on the car. The bridge drive drum clutch and locks, the car control linkage, the implement lift control linkage, and the transverse row indexer are controlled through a hydraulic system on the bridge. There is no hydraulic-connection between the car and the bridge so that hose connections therebetweenare not required.

Referring to FIGURE l1 for details of the controls,

cable drum 110 is mounted for axial, movement on its shaft to be moved through yoke 22d-'by cylinder 226 to engage ,clutch 222. Spring 228 holds clutch drum 11! d1sengaged from clutch 222 and engagesfthe drum with a Vlock 22.3 which hold-s the drum from turning and so locks the wheels of the bridgewhen the cylinder 226 is exhausted.- To one of the casters is detachably secured two control lugs or cams 96 each on an opposite side of bracket 90 and parallel to the axis of the wheel. A three-way cam valve 23) is shown engaged with one of `the `two lugs 96 on the swivel bracket of a caster 44.

Valve 230 is closed by a lug 96 onlyiwhen the axis of the caster wheel is parallel to the length ofthe bridge. There- 'i fore valve 236 is open on narrow gage, turnarounds, and Crossovers.` A three-way cam valve 236 is provided at the "right-hand end of the bridge tov be engaged by the car at that end of its run.v A three-way cam valve 236 is optionally provided at the left-hand end of the bridge to be engaged by the car at that end.

The hydraulic circuits for controllingthe bridge drive cylinder 226 are suction line T1 from tank 232 .to inlet side of pump 234 driven from belt and pulley connection from motor 1112 (see FIGURE l), from the outlet of vpump 234, lines T2 to T3 to the inlet port of three-way carn valve 236 and` from T3 to T4 to the inlet port of caster lug camvalve closed only whenthe casters are `turned at right angles to the bridge (transverse) and otherwise connecting to outlet line TS-toline T6 to the der 27S.

Valve 240 has a top and a bottom inlet-exhaust port, a side outlet port, and a piston or spool for sealing ott either the lower or upper port according toy its position. The outlet of valve 240 is connected to the bottom inlet of Valve 240". The `outlet of valve 2411 is connected to cylinder 226 to engage clutch 222 when pressure is received at the cylinder. Valves 236 and 236 are normally exhausting spring returned. The upper inlet port of valve 240 is connected through Valve 236 in normal position to line T7 to tank v232 until the car presses the lever 237 of valve 236 in blocking its exhaustV line and connecting pressure from line T3 to the topport of valve 246.

Similarly the upper inlet port of valve 240 is connected through valve 236 in normal position to line T8 to Vline T7 to tank 232 until the car presses :the lever of valve 236' in, blocking its exhaust line and connecting pressure from line T2 to the top port of valve 240. The side outletpof valve 240 is connected to the top port of valve 240". If valve 236 is omitted valves 240 and 240" would also be omitted, and the outlet of valve 240 would be connected to cylinder 226. Valve 230 has a lower exhaust port connected to line T4 to line T7 to tank. Cylinder 226 under the force of spring 228 exhausts toV tank through top port of valve 240" to center port of valve 240,' from top port of l valve 241)', valve 236 to line TS, to line T7 to tank, since the valve spools of valves 246, 240.', and 240 drop by gravity and permits fluid, drawn from storage tank 232 by pump 234 to enter cylinder 226 enabling the bridge to operate. y Hook latch 23S is provided to latch valve 236 open for continuous operation of the bridge for longitudinal cultivation. The clamping of drum 110 to the frame zarsen-es should hold the tiller during movement of car 126 across ders on the car are from hydraulic tank 246, suction line T10 to inletv of pump 148, line T11, line T12, line T13, inletport of four-way two-position reversing valve 242 to upper orlower outlet ports according to the position of valve 242, which in the position shown connects to the ,lower outlet port from which line T14 connects to the head end (lowering end) of cylinder 174, and from line T14 a T connects line T15 to the inlet end of check 1 valve 248, the outlet of which is teed into the rod end of cylinder 174 to lift cylinder 174. Line T16 from the upper outlet port of valve 242 runs to the head end of cylinder '174' and by T-from line T16 to the inlet end of check valve 248, the outlet of which is teed into the rod end of cylinder 174. The upper outlet port of valve 242 is now connected by passage in the valve to the exhaust port. Line T18 from the exhaust port connects to line T19 to tank 246. When Valve 242 is shifted its inlet is connected by passage to the upper outlet port and Yits lower outlet port is connected by passage to exhaust by linkage 243 which extends beyond the ends of the car and at the ends of the bridge hits stops 244 which reverse the position of valve 242. Check valves 248'and 248 preventl the lowering of the implements when valve 242 is reversed. Check valves 248 and 248 are respectively bypassed by normally closed similar double-pilot-piston two-way valves V 256 .and 25,6 ,one pilot cylinder of which is larger than pumpy 148, line T11, a three-way two-position cam valve 262 normally exhausting which when pressed in connects pressure to 'line T20 from which lines tee ot to respectivelyl the upper and lower port of the small pilot cylinders of valves 251) and 256 and to the rod end of cylin- Pressure is also connected from pump 148,

Y S r line T11, line T12 to the input port of normally closed cam valve 262' similar to valve 262, which when engaged opens to 'line T22, line T23 which tees to the top `and bottom port of respectively the small pilot cylinders of valves 250 and 256. A T inline 22 connects to a hand valve V whose outlet is connected by line T24 to the head end of cylinder 273. Valve V is left open except as noted under operations, u Y 4 A spur gear 256 is keyed on a shaft 50 on truck 34. Spur gear 258 is rotatably secured on a lever 264 pivotally secured on lthe bridge to engage gear 256 and has an arm with depending inger 259 which engages the arm 260 of cam Valve 262 on the end of car 120 toward truck 34. Lever 264 is connected to linkage 124; Linkage 124 has a linkage rail 266 which extends the length of the bridge and is actuated by spring returned cylinder 26S connected by line T5. Cylinder 268 When pressured forces down linkage rail 266 and disengages gears 256 and 258` when casters 44 are turned from the wide gage.

Dropping of linkage Vrail 266 opens a threeway valve 270 on car 1120 by means of a valve spring 271 which actuates forked lever 272 having Wheels 273 and 273 either of which rides on the linkage rail throughout the length of the bridge depending on the position of the car. Valve 270 when open to pressure insures that both lift cylinders 174 and 174 are raised'by in series from pump 148, line T11, line T12, inlet port of val-ve 27@ which is normally blocked. The lowering of linkage rail l266 opens valve 270 to pressure against its spring connecting line T12 to the outlet port line T26 teed to the lbott-omisV of the langer pilot cylinders of valves 25)` and` 250 and the input port of cheek valves 276 and 276, whose outlets are connected to respectively the lift ends of cylinders 174 and 1,74. Check valves 276 and 276 prevent fluid tlow from one lift cylinder to the other, hold these cylinders raised when valve 270 opens to Aexlia-ust, and holds pressure connected by valve 242 through either valve 250 or 250 to cylinders 174 or 174 respectively.Y In the normalposition of valve 270 line T26 is exhausting to line T12 to tank 246.

Spur gear 256 is fastened to turn with a drum 49 on truck 32 when indexing Vof the bridge at both ends of the cars tnavel is desired. Spur gear 258', similar as gear 258, is engaged with gear 256 lby lever 264' connected to linkage 1:24 to disengage gears 256 258 whenever linkage rail 266 is dropped. Finger 259 Isecured on gear 258 engages arm 261)' on valve 262 located on the left end ot the car. When either valve 262 or 262 is eng-aged by lingers 259 or 259 respectively the indication -is that the bridge has indexed the proper dist-ance for the next transverse run of car 120. If the bridge is to be indexed only when the car is at one end, a stop such as block 345 is placed to be engaged by. Ivalve 260 or 260'. The engaging of valve 260 or 260 reverses the car and implements.

Valve 262 upon openingcloses valve 256 and opens valve 250 dropping implement 178, the car being at truck 34. Valve 262 upon opening closes valve 250 andopens valve 250 dropping implement 178', the car being at truck 312. Valves 2612 and 262 are the only means by which valves 250 and `250' are opened, therefore .only lone valve 250 or 256 is opened at one time. (Valve 270, when opened, insures that both valves 250 Vand 254) a-re closed, but knever opens these valves.) The valve 250 or 250 whichwas opened by action of the index nger 259 or 259 lrespectively exhausts the rod end ot implement cylinder 174 or 174 respectively throughout the nun of the car across the bridge; but upon linkage 243. reversing valve 242 at the end of the cars run the cylinder 174 or `174 respectively islited, and the opposite cylinder 174 or 174 is held up by valve 250 or 250 respectively remaining closed.

Car control linkage 122 is provided with a lower and upper linkage rail 162 and 163 respectively pivotally attached to opposite ends of lever linkage arms 284 pivotviding a parallelogram movement. Valves 262 and 262' `alternately reverse the cylinder 160 to shift wheel 158 from the lower to the upper car control rail yand vice versa whenthe car engages alternate ends ofthe bridge. And a locator 286 is xed on the right `handpend of the linkage rail 163 and another 286 on the opposite end of rail162. i Row locators 290 are` detachably clamped to the linkage rails 162 or 2163 to locate longitudinal rows as desired by the farmer. The locators cam wheel 1158 to a neutral area between the linkage rails, stopping the car with wheel 158 resting in Vrecess V292 on the locator 290. Sale markings 294 on rails 162 and 163 facilitate .positioning row locators at proper intervals. Linkage rail 162 is pivotally linked to lever 296. pivoted at 297 to thebridge or truck 34, and linkage rail 162 is `forced toward the right and upwardV by a strong spring 298 acting on lever 296, rail 163 being forced thereby toward the left and downward. `Cylinder 160 is not eiective in moving the linkage rails against the force of spring The normal position off the car control linkage shown is called INTERMEDIATE-RUN-POSITION. When wheel 158 is carried far enough olf rail 162 or 163 as by row locators or end stops the position is called STOP- POST-'HON or NEUTRAL; since wheel `158` is` forced to the middle area if look clutch 152 or'153` was engaged it is thereby released through action of yoke .154. When a single acting cylinder 302 which is linked to lever 296 is pressured, lever 296 is forced opposite to spring'298 and the control rails are spread wide `apart `in this position called START-POSITION, whereby the car is started from its position when wheel 15,8 was in NEUTRAL. A i

two-way pressure relief valve 303 connected across the ends of cylinder 16) is set to relieve the cylinder of pressur-es above the line pressure, whereby the cylinder can i follow the vertical movement of wheel1-58.

An` index-stop lever 304 actuated by index-stop control 186 operates a three-way valve 306-spring returned to exhaust. When .stop 186 moves lever 364, to the position shown in dotted lines fluid is connectedl from pump 234, line T30, inlet of valve 386 opento outlet port,

`line T32 teeing to` inlet-of check valve 368 and bleed valve 316, whose outlets are connected to the headend of cylinder 382. After lever 304 passes stop 186 cylinder 302 is returned slowly to normal position by exhausting through bleed valve 316 under force of springV 298, after car 120 is well on its way to the next locator or end stop 286 or 286. When wheel 158 is on an end stop and a stop 186 actuates lever 3042wheel` 158 rides into a recess 312, and thereafter when cylinder 302 exhausts after stop 186 is passed wheel 158 is forced against limit switch 314 which opens the ignition of engine 182.

` lt is preferred that car 120 should be stopped when the bridge is moving except during indexing of the car in longitudinal operation. Accordingly the end stops run wheel 158 into NEUTRAL at the ends of the bridge until the lock yoke is shifted by movement of `ringer 259 .or 259', or row locators 296 hold wheel l158 in NEUTRAL by bolts 338 through holes 340 in block 332 clamp the block to either rail 162 or 163. Brackets 336 can be bolted through different holes wherebylinkage pieces 284 are avoided enabling the locator to be placed anywhere along these rails between the end stops.

The procedure for automatic transverse operation is as follows:

Arrange the car and implements for transverse opera-` is not to index when the car reaches that end. Start the engine with the transmission in neutral and the power take-off disengaged. Pump 234 should start. Put wheel 158 `in neutral as bylplacing a row locator` under and another above the wheel. Check that valveVis open and valve 236 unlatched. Engage the power take-off through hand clutch CH. Car rope 132 starts car pump 148. The implements should' lift with the tiller on narrow gage,` since caster valve 230 is then open, connecting pressure to cylinder 268, which drops rail 266 to permit spring 271 to lift-valve 270, which then connects pressure to the rod ends of cylinders 174 and 174. Remove all roW locators; the car will run to an end on the bridge at which thebridge indexes and the car will then stop, since wheel 158 runs` onto an end stop 286 or 286', `throwing lever 154 to neutral, disengaging respectively `down track to field F. When-the castersswivel crossf2.5V

wise into` the field and reach an angle approximately 90 `degrees to the length of the bridge castervalve 230 closes, exhausting cylinder 268, engaging the indexing control gears 258 and 258. Consider the car to be at the right hand end of the bridge.` Finger' 259 opens valve 262 Vwhich shifts cylinder`160 lowering wheel 158 to rail 162 and reverses valves 258 and 250 lowering the implement 178. As cable drum 136 is stopped from-revolving by engagement of clutch face 158 with 152 the cable starts to pull the car toward the vopposite end VVof the bridge.

Implement 178 is dropped at the desired speed selected according to the orifice sizefused Vin valves 250. As the car leaves the end of the bridge valve 236 is disengaged and exhausts cylinder 226 stopping thebridge. When the car reaches the left hand end of the bridge the lift actuator' 243 is shiftedlifting the implement 178, and linkage wheel 158 rides into NEUTRAL on end locator `286 stopping the car as it opens valve 236 starting the bridge in motion; Index finger 259 opens the reverserelease pilot valve 262 `momentarily thereby reversing valves 258, and 250 andcylinder 160, starting the car toward the righ-t end of the bridge and lowering implement 178 for the second run of tillage; whereafter` the process is .continuously `repeated until the, castersV enter the crossover curve opening caster position valve 230. The'opening of valve 236 connects pressure to cylinder 268 to lower linkage 266, disengaging the index gears, prevent- Vthe car during the crossover.

ing the lowering of an implement andthe movement of The foregoing process is repeated as when the bridge irst turned into the ield. When the turnaround 184 is reached with transverse operation index valve 386 is opened by the end-of-thei line index-stop` 186 and held open while` wheel 158 rides Secure row locators on rail 162.

Close valve V.Y Proceed as with transverse operation..

into recess 312 in an end locator. After the field located index-stop is passed cylinder` 302 exhausts and wheel 158 trips limit switch 314 opening the engine ignition. Operation is resumed by manually removing wheel 158 from recess 312 or by bypassing the open limit switch with hand `switch 316.

The procedure for manual longitudinal operationfis similar to"transverse operation except as follows:

Arrange thecar and implements for longitudinal operation. Move the car to the right hand end of the bridge. Hook valve 236 open.

After pressure comes on, the implement lifts as when setting up for transverse operationf Press invalve 262.

Open valve V until wheel 158 Ais`forced against rail 162; then close valve V. Wheel 273 engages rail 266.

'Position linkage 243 so that the desired implement is ready to be dropped when its check valve bypass valve Vimplementr178 or valve 262 for implement 178'.

Vas at the start.

Y through the crossover.

lli

Start the bridge in motion. Whenthe bridgeturns into .the field, with the car stopped at a row locator, lower the implement desired by pressing in valve 262 tolower At the endof run A the implement is automatically lifted The crossover switches 'are located far enough ahead of the crossover tracks so that the implelment will be lifted before the crossover track is reached.

Linkage 243 is manually reversed, and then by pressing in valve 4262V or 262 the desiredimplement i-s manually lowered. On each run Lthe implements are manually lowered when desired ,and a-utomatically lifted and held As the bridge continues back and forth the car is indexed at each index-stop until the 'bridge is automatically stopped when the car'reaches the end of the bridge and .subsequently contacts an'indexpstop. With' the indexstop properly located along the curvethe implements are raised during the indexing of the car.v

Automatic lowering of the implements during longitudinal operation is provided by adding to thel tiller the linkage and vcontrols shown in FIGURE 17. Valves 2162 and 262 are' linked together by rod 350. Rod 350 is secured to linkager243 in the proper position'by cross member 351. .The cam` wheel of valve 262 is held to rail 354 by spring 356. Rail 354 extends the length of the bridge,'is supported on linkage arms 358, andris linked tothe piston of a springcentered double-acting cylinder 360. Cylinder 360 is controlledby cam valves 362 and V362 both similar to valve ,230 and placed on opposite sides of a caster 44 to be opened by a detachable lug placed on the casterso that the desired 'valvev is' opened when the casters are onone run and is alternately opened during every yother run the other valve being opened during intervening runs of the bridge. Hydraulic connections are made from the outlet of pumps 234 line T2 teeing to the inletof eachvalve 362 and 362 which are shown in their normally closed inlet position.

The outlet ports of valves 362 and 362 `are respectively connectedl to theV left and right hand endsof cylinder 360, and the exhaustA ports are teed into line T7 to tank A232. The engaging `of the lugwi-th valve 362 connects pressure from pump 148 to the right hand end of cylinder 360 forcinglinkagerail 354 toward the carshifting linkages 350, 351, and .243, opening valve 262, closing valve 262', and reversing valve 24,2. Then valve 262 connects Apressure to open pilot valve 2,50 and close valve 250', exhausting through .valve 262', but does not operate cylinder'160, since valve V is closed. Cylinder 174 then exhausts through valve 250, dropping implement 178. ,Valve 242then connects pressure and exhaust lines to lift cylinder 174 and lower cylinder 174' whose lifting port is open through valve 250 dropping implement 178'.

Complete automatic longitudinal and transverse operation is provided with the tiller disclosed in the foregoing discription.

Y FIGURES l2, 13, and 14 illustrate two somewhat different forms of track guided farming devices. Referring to FIGURE 12, bridge 30a is pivoted on trucks 32a and 34a at 366 andV 367 respectively. Two grooved wheels 46a are engaged with each rail and rotatably secured to the frame of each truck. The wheels of truck 34a are stopped when the leading wheel of this truck hits track end-stop E; the other truck 32a continues around a semicircle 370; and truck 32a, bridge 30a, and implements hits end-stop E7; Iand trtuoky 34a round-s ycurve `370. Simple two-way switches 372 and 373 similar in principle to three-way stationary switches 191 are provided. Turns between successive runs are made similarly by alternate trucks. No implement lift is needed for longitudinal r transverse.Voperationof many implements. This tiller andthe one shown in FIGURE V13 can have many of the features shown for thepreceding tiller which are not repeated here. Y Y

' FIGURE 13 shows the tiller of FIGURE 12 slightly modied in that the wheels are mounted in swivel caster frames 374. The area required to turn is reduced with the truck and bridge arrangement shown in FIGURE 13, since curves 376 and 377 are small. The truck 34h is forced back as truck 32h makes turn376 and truck 34b returns to the end of the rail E as the bridge b straightens across run B as truck 32h completes turn 377. The

. turns between successive runs are made similarly by alternate trucks. The implements are lifted while the bridge is manually turned on the crossover.

A simple drive is shown in FIGURE 14 suitable for which is secured beveled gear 386. Beveled gears 387 and 388 secured on sleeve 389 which is splined on shaft 390to slide beveled gear 387 and 388 to engage beveled gear 386. Sleeve 389 is provided with a slip ring 392 and yoke 393 which is linked to end-of-the line reverse levers 394 and 395 which engage actuators located to engage levers 39,4 and 395 alternately at opposite ends of the'line toshift gears 387Y and 388. While the gears are shifted clutch 384 is camrned open by lever 396, pivotedV at 397, having a rollerA 398 thereon arranged to Vroll along flange 399 on clutch 384as the clutch turns and a cam 400 with two recesses which'engage one of two dowels 402 secured radially to slip collar 404 about sleeve 339. The other dowel is` inserted in a slot 406 in the bridge whereby the slip collar 404 is prevented from revolving with sleeve 389 but moves with the sleeve axially as the yoke 393 is shifted, lever396 being cammed by the shifting of pin 402'on cam 400 to open clutch 384 against its spring 408 when the yoke is shifted. Such a reverse drive is approximately shown in my Patent 2,768,757.

Bridges 30a and 3017 are each simply propelled by two land wheels 410 supported nearthe ends of the bridge each on a shaft 412 pivotally secured to arms 414 pivoted on shaft 390 wherefrom the wheels 410 are driven by chain and sprocket drive 416.

Bridges 30g and 30h are also optionally propelled by rail drives. A nonswivelgrooved-wheel pivoted-truck drive is illustrated on the left Vhand truck of FIGURE 14. Grooved wheels 46a each on a shaft 418 are driven by chain and sprocket drive 420 fromV parellel shaft 422 having vits axis through and at right angles to the axis of the truck swivel. On `shaft 422 are secured two similar beveled gears 424 and 425 Ywith the vertex of their pitch cones on the axis of the truck swivel. Beveled gear 426 secured on shaft 390 coupled to shaft 390 by universal joint 428 meshes either gear 424 or 425 when the truck is crossways the bridge but disengages when the truck is stopped while the bridge pivots on this truck. The opposite truck drives the bridge around the semicircular curve 370 or 270', but this drive disengages on curves 376 and 377. Gear 426 re-engages the opposite gear 425 or 424 when the bridge completes its turn, and the truck about which the bridge pivoted is driven away from stop E or E in the `reverse direction. i

This swivel-truck drive is adaptable to swivel casters `as shown onthe right hand truck of FIGURE 14. Drive 420 is replaced with beveled gear 430 secured on shaft 422 and engaged with'beveled gear 1431 on shaft 432 on the axis of the truck pivot. Shafts 434 each on the axis of a caster swivel are `driven by chain and sprocket drive 436 from shaft .432. Casters .441; are similarly driven from shafts 434 as casters 44 are from shafts 50.

The threedrives shown in FIGURE 14 can be cornbined on one tiller as illustrated. Where transverse tilling is required either rail drive alone is preferred to the land s is f I i xraction wheels because v of `the land taken `for` these wheels to run on.

Fiennes and 16 inserate a two-span bridge finer- *whereby rails C `and 38C are spaced: at a considerably greater distance than is practical with a single span.`

Truck 34 is replaced by truck 448 which allows car 120 to pass from span to span. Provision made for hinging bridge span 30 to span Sil for vertical movement and the cables and controls are extended to the end of the second span 31)' whose one truck 34 is similar to truck 34. Additional spans 39 each with a truck 448 can be added for criA r i 14 pulleys 57@ are provided on car 12M for supporting cable 4Car traction wheel 5d?. is mounted on shaft 574 bearing in two arms 576 which are pivoted to the frame of car 12de'. ArmsS'd are lifted by cylinder 57S to disengage wheel 552 from the ground during transverse movement 4of car 129g?. Wheel 562 is driven through chain and -fsprocket drive 531) from shaft 531 on the pivot of arms Vwider spacing of the rails. The spans are hinged together 576. vBeveled gear `582 secured on shaft 581 is engaged with beveled gear54 which has a clutch back 153d and is rotatable on shaft 138:1 whercon also is mounted the cable drums 13d and 137 similarly as `on car 120.

The control circuits for truck 52)` and car 129:1 provide fortransverse operation of car 12M between trucks 52tland 552 and the indexing of car 12M each time it reaches truck 52d.

Beveled gear 584has a ratchet wheel surface 586 around the hub thereof. Ratchet 587 is secured to the channel sections 456 and 458 are pivotally attached to i and in alignment with channels 116 and 118 on the axis of pivots t) which axis also passes through the center of these channels.

Channels 456 and 458 are cut'on an,v

angle at 46d to rest against channels ldand 11S' of sec-l tion 31) also cut on this' angle. The linkage rails on adjacent bridge spans are connected by flexible links 462 'piston of cylinder 538 to engagewith ratchet wheel 58S.

Spring 552 releases ratchet 557. Double acting cylinder .ldd actuates yoke 154d whereby either clutch156 on drum 135 is engaged with clutch face 152 on the cars frame or clutch 151 on drurni137engages clutch 153d on beveled Y, gear 554. Spring 142 separates clutch faces 15) and 152.

each having a pin secured at each end lthrough a slot in p the adjacent end of the rail. VThe end stops would be only at the ends of the bridge so that the levers can travel on linkage rails from span to sp`an.."j` A centrally* located pivot plate 464 on truck 448 and a pin or socket 465 on span 3d are engaged when the bridgehinge is uni hooked, providing a convenient means to move the string of bridges around curves.

tinuous cable 132 and `longitudinally propelled traction wheel 502. i

and spring 143 separates clutch faces 151 and 153:1 as

-on car 121). The four-way cam valve 590 is Vlocated 0n the end of the car facing truck 521), and a three-way cam valve 252 is located on the end facing truck 552. Fluid connectionris made from tank 246 by line T1 to pump 148 FIGURES 19 and 2l show a variation of the tiller i wherein the `car Hdd runs on swivel land casters 500 and 4is transversely propelled similarly as car 12() by conby its own,

Parallel tracks 504 and 506 are laid outalongopposite` 'i i sides `of the field. Each track comprises two angle rails 508 and 5G? spaced apart at intervals by' channel members 510 which are provided with holes 512 that iit over bolts 514 imbedded in concrete pier 516. The track is fheld in place by nuts 5,18 whereby it can be removed and relocated.

Truck 52.1) on track 534 is provided with a DC. electric gear-,motor 522 taking power throughv arm 52.3from1conf.

ductor bar 524 mounted on insulators 525 on the under side of rail 509 and using rails 508 and 599 as return conductors. The gear motor'is in series with hand switch 526 and lever switch 527 Aopened by stop 186d located Y projecting from the ground atthe end of thel run. The

gear motor drives shaft 528 vertically mountedto the truck. Cable drum 130vis splined for axial movement on shaft 528. Cable drum 110 is free `to rotate but axially held on shaft 528. To 'the facing viianges of drums 110 `and 134) are secured beveled gears 534 and 536 respectively. Beveled gear 534 is in mesh with beveled gear 538 on shaft 540 which drives through chain and Sprocket drive 542 shaft 544 on which twogflanged wheels V546 are xed. Shaft 544 is rotatably secured to thev frame of Y truck 526. Yoke 550 controls the vertical movement of drum 130 engaging the beveled gear 536 thereon with beveled gear 538 to drive drum 110. i

A second truck 552 is propelled from the power truck 520 by an endless cable 48d around drum 110 on truck 521) and about drum 49 on vtruck 552.` Drum 149, secured on vertical .shaft 556 at the top drives beveled gear 558 secured'on the bottom of shaft 556 to' mesh beveled gear` 560 secured on shaft 562 and wheels 546 `secured on shaft 544 through chain and sprocket drive 568 similarly as on the power truck 529. Drum 134 is rotatably secured on shaft 555. About drums 13) and 134 between the trucks is'run the endless car power cable 132 which drives drums i 136 and 137 similarly as on the car 120.` Cable guide `and "romfpump 14Sby line T12 to inlet of four-way valve 59), passage in valve 59d opened in normal position to line T44), tceing to the head ends of cylinders 573 and `58S. The rod Vend of cylinder 17461 and of the cylinder T44 to lift cylinder 174d andreverse valve 6th) and con-V necting line T49 to exhaust line T19 to exhaust cylinders 573 and 538 respectively lowering wheel 552 and releasing ratchet 557 to free drum 137. Valve 262 in normally exhausting yposition connects the head end of the cylinder of valve 695 to tank 245'. Valve 262, normally exhausting, is opened to pressure by engagement with truck 552. Valves 59) and 262 when engaged with their trucks thereforer reversely connect uid from pump 14S to opposite sides of the piston or epooliof four-Way pilot valve 66). Valve odd which remains in position when valves 59) and 262 exhaust connects'fluid from pump 14g to either side of cylinders 16() according to which valve 5% or 594 had engaged `its truck last. Fluid connection is made from pump 145, line T11, line T42, inlet of valve dt) shown-connecting `to line T43 to cam valve 61).?. normally closed and with tee to the top port of valvc240d. When j valve 652 is opened it connects line T43 to T45 to the head end of cylinder 169 with T to the side port of valve 24tld. The rod endv of cylinderdt) is connected through valve 61N) to line T19 to tank 246. Valve 692 on carlZtld engages arm 694 on truck 52) to stop the indexing of car 129e?. Valve 662 is connected in parallel with the normally exhausting port of valve 59) through selective check valve 24M the output of which is connected to cylinder lo@ so as to engage clutch 15351 under pressure.

Upon car ltld reaching truck 52d both truck 526 and car 12th! index together. Truck 52) moving slightly faster than car 12M reaches its proper location and extends arm 604, which car 12M soon bumps initiating the return trip of the car'.

A stick limit switch 696 on truck 52() is closed by movement of car :1 thereagainst to start the index movement of the truck. lA circuit is completed by switch 605 in- Y indexed the desired .amount at which time the contact' arm leaves switch 6Std), which is slowly returned by spring under the delayl of dashpot 613 to its normally closed position. While switch 616 is open (returning) switch 666 opens by the movement of the car 12641 away from the truck 526. Y f

Truck 526 has an arm 664 pivotally secured thereon to swing out toward carl 12th! after the truck indexes the desired amount. Arm 664 is operated by solenoid 614 by a circuit completed from across rails 524 and 562i and including in series shoe523, line Lil, front contacts and l'coil of stick switch 666 in series, line L2, solenoid 614, normally open limit switch 616 mounted on arm 604 to be closed by carllZtl, line L3 to rail 508. By this arrangement arm 664 ris extended nlyafter car 120:1 hits stick switch 666 until it hits arm 604. The slow movement of the arm pr-ovided by dashpot 618 -and the fact that the trucks index faster than the car insures that they car will not bump the arm before the index is complete. Car 12M is indexed when valve 590 engages with truck 526, opening valve 596, which exhausts cylinders fence can also serve as a bump rail.

elsa/ice Y i6 spaced at intervals therealong to drive into the ground. A

A Vehicle 630, herein called a` truck, having wheels r 646 to travel ori track 624, is propelled by gear motor634 v61",@ and car 120e.

through chain and sprocket drive 636 about axle 633 to which two track wheels 640 are secured. The truck carries a light or other source of radiant energy 642 and shielding 644 and lfocusing means 646 for directing the` energy into a narrow beam or sheet to guide car 120e between 'truck 636 and stop rail 626. A light baiiiing 648 around'the light source blocks stray rays in line with the light source. The source v642 and shielding 644 are preferably supported onan upright member .651 which can swivel and lock atfany desired angle with respect to track 624 to direct the car 126e along the desired angle of Working.

Lamps 684 and 685 control' the indexing of both truck Lamps 684 and 685 are supported on arm 686 extending from the end of car 120e which faces truck 63@ and directs light parallel this end of ,the car.

' Truck 636 has a barile arm 656 extending toward car 578 and 566, reverses valve 666, lifts the spool of valve 24661 connecting pressure to the head end of cylinder 166, and connecting pressure to the rod end of cylinder 17411 liftingthe implement. When cylinder 57E exhausts, j

now connecting pressure on the rod end of cylinder 166 f' whose exhaust is blocked by cam valve 602. Valve 602 is positioned to engage arm 604 to open. When the trucks have indexed, stopped and arm 664 is extended, theV car engages arm 664 opening valve 662 which exhausts the head end' of cylinder 166 reversing lever 154, engaging clutch 156 to the frame to lock drum 136 to pull the car away toward the other truck.V Drum 137 is lifted by spring 143 disengaging clutch 151, stopping wheel 502. Valve 49? reverses when disengaged from the truck, connecting pressure to cylinder 578 to lift wheel 562 from the ground, and to cylinder 588 to lock ratchet wheel 586. Valve 590 exhausts cylinder 174e! to lower the implement,

drops the spool of valve 246 to provide an exhaust bypassV for the head end of cylinder I6@ around valve 662 which closes when the car and truck separate. does not shift lever 154ml until Valve 662 is opened upon hitting arm 694 exhausting the bottoms of'cylinderll6t whereupon pressure through valve 606 acts to shiftrlever whereby the trucks are held against the pull of the cables.

Referring to FIGURE 20, telescoping bridge frames 626 and 621 are added, connecting truck 520 to car 12tld and car 126e? to truck 552, whereby the car is guided in its movement between trucks with greater precision than obtained with the cable drive alone and whereby the trucks are maintained vertical even with wheels 619 removed.

FIGURES 22-29 show another variation of the automatic guided farming device and further features applicable to the described forms. A feature of these figures includes the application of beams o f light for guiding and controlling thetiller. i

Y According to the subvariation shown in FIGURES 22-24 a portable track 624 is laid along one boundary "627 of structural steel horizontally supported on legs 628l Cylinder 166 rows, arm 612e isractuated by index-stops 186e.

e with a photoelectric cell 652 thereon to intercept the n' light beams from lamps 684 and 685. The photoelectric cell isconnected across the coil ofv a sensitive relay 656 whichhas front contacts closed when the light of lamp 634 or 685 shines on cell 652. Relay 656 closes a circuit from the positive of battery 632, switch-166i) (closed), switch 616e, front contacts of relay 656, pullin coil of stick relay 656 to the negative of battery 632.V Stick relay 656 is thereby energized to close the circuit of motor 634 from the positive of battery 632, switch 660, switch 616e,

hold coil and front contacts of stick relay 65S, switch 662, motor- 634 to the negative of battery 632. Truck 630 then runs along. the track until this circuit is opened either -manually by switch 660 or after apredetermined index at which time switch 610e is opened dropping relay 658. Switch 610e is delayed from closing by dashpot 613e until the implement car leaves the truck, removing lamps 684 and 685 from cell 652, dropping relay 656 leaving the motor circuit open after switch 610e recl-oses.

Index limit switch 610e is opened by a lever arm 612e. Arm 612e can be operated by'a turning arm 259 as in FIGURE l1 or, where itis desiredto accurately retrace Indexstops i866 are steel or wood postsY placed in the ground at the desired intervals to stopthe index at the desired spot. Arm 622e, spring biased away `from switch 610e, first engages the bottomV of 186e as viewed in FIGURE 24, rotating 612e clockwise'against its spring and engaging switch 610e rotating it counterclockwise. Lever 612e has contacts which hold the motor drive circuit in parallel with switch 610e as lever 612e opens switch 610e so that the truck continues to operate until lever 612e. passes stop 186e' to be restored by its spring to theV position shown in FIGURE 24. Switch 610e is delayed from closing by its ldashpot 613e which holds open the motor circuit stopping the truck which causes the car to move away as will be described, disengaging lamps 684 and 685 from shining on cell 652, dropping relay 658, preventing the reclosing of the motor circuit until the car returns. This control feature is also applicable in the preceding embodiments herein described; Y.

The novel implement car 129e is provided with a four wheel caster drive complete with engine 102e. Each caster 664 horizontally swivels and has a sprocket tooth rack-92etaround the swivel bracket thereof.` The casters are aligned and connected by chain 665 around the four equal caster sprockets 92e to maintain alignment. Sprocket 663 engaging chain 665 steers `the four casters together. Sprocket 668 and a spur'. .gear 670 are secured on a vertical shaft 669 to turn together on theframe of the truck. A gear rack 672 is engaged with spur gear 670. The rack is arranged for lengthwise movementin groove 676 on the frame of car 120e. The rack is secured on the rod of cylinder 674 secured to the frame of the tiller for actuating the rod. The car will not be turned around by the drive, since the caster wheels all turn the by interruption of light beams with bale `650. Photoelectric tubes 680 and 681 each having a tubular light shield 682 are placed opposite lamps 684 and 685 also having shields 682. The shielded lamps are horizontally spaced on arm A1, and the shielded tubes are arranged on arm A2 so that each light shines parallel only on one tube. The arms extend from the end of the car` facing the truck to straddle baffle 650 on the truck to break the light beam from the outermost lamp 684 from reaching its outer tube 680, and then as the car approaches the truck both lights reach their tube, but as vthe car approaches still closer only the inner light 685 is shielded from reaching tube 681. Lamps 684 and 685 are connected across battery 688 in a circuit from the positive of battery 688, hand switch 689, line L20, lamps 685 and 684, line L22,

all in series to the negative of battery 688. Tubes 680` and 681 close circuits from the positive of battery 688, switch 689 to line L24 in series and from line L24-in parallel tubes 680 and 681 each inseries with the coil of relays 686 and 687 to the negative of battery 688. Relay 686 closes a circuit from the positive of battery 686, switch 689, line L20, line L28, back contacts of relay 686, coil of solenoid valve 690,l line L30 all in series to the negative of battery 688.` Relay 687 closes a circuit from line L28, back contacts of relay 687, coil of solenoid valve 691, all in series to line L30. Spring returned threeway valves 690 and 691 control steering forindexing the car. t

. Connection is made from pump 148, line T50, line T51, oriice 692, normally closed inlet port of valve y690` which when opened connects to line T52 teeng tothe upper pilot port of valve 716 and to the upper inlet port of valve 717, which opens to side port, line T53 to `the right hand end of cylinder 674. In normal position shown valve 690 connects line T52 to line T56, to T58, to tank 246. Connection is also made from line T51 by T ahead of orifice 692 to line T60 to the normally closed inletport of valve 691 which when opened` (as shown) connects to line T61 teeing to the upper pilot port of check valve, 717 and to the upper inlet port of check valve 716, `which opens to side port, line T62 to the left hand end of `cylinder 674. Switch 689 is closed to turn on lights 6,84 and 685 during operation. These lights energize cells 680 and 681 respectivelyto lift` relays 686 and 687, deenergizing the solenoids of valves 690 and 691, which exhaust fluid from the tops of valves 716 and 717 respectively,enabling these valves to be controlled by their lower pilot cylinders, i.e. by the steering control of cells 694-696. v

Then when cell 694 for example receives light to open valve 704, pressure is connected from pump 148 through valve 704 to the pilot cylinder of valve 708 forcing the spool of valve 708 down, `which connects pressure from line T50 to line T60 to the lower inletof valve 716 and to the lower pilot of valve 717, lifting valves 716 and 717. Valve 716 then connects pressure from line T60 to the left hand end of cylinder 674 which moves the piston out exhausting the rod end through the lower inlet of valve 717 opened by the lower pilot piston therein and throughvalve 709 to the tank. Thus when light 684 is shielded from'tube 680 by bale `650 relay 686 drops, energizing valve 690, connecting uid through orice 692 `to the;`

and when light 685 is shielded fromtube 681 byballe` secured parallel in eachend. The spool and extension slide up and down in a' conforming housing H which is recessed around the middle of the inner wall. Into this chamber the side port is tapped. The ends of the spool chamber are ported and labeled INLET and the ends of the exhaust controlling piston chambers are ported and labeled PILOT. The pistons open the valve for exhausting.

The car is steered along the transverse runs by light from sourcer642 directed to, one or more of three narrow vertical photoelectric cells 694, 695, and 696 having shielding partitions^698 extending perpendicularly from the boundary edges thereof whereby considerable vertical movement of the car does not change the relationship of the light reaching these cells. The output of each cell 694, 695, and 696 is amplified by amplifier 700, 701, and

702 respectively across whose outputs are `connected to two-port normally closed solenoid valves 704, 705, and 706 to operate when cell694, 695, and 696 receive light from lamp 642. i

Valves 704, 705, and 706 control pilot valves 708 and 709 by connections from tank 246 to inlet of pump 148,

and from the outlet of pump 148 by line T50, T to valve 704, to head end ofthe control cylinder of valve 708 and a T from line T50 to valve 706, to the head end of the control cylinder of valve 709. The control cylinders'of valves 708 and 709 are exhausted to tank from the head end respectively` each through a` check valve 712 whose outlets are Td `to line T64 to valve `705, Whose outlet is Td to line T57, to T58,-to tank 246. Check valves 712 prevent ow between the cylinders of valves 708 and 709. Valves 708 and 709 are spring returnedV two-position three-way pilot valves shownV in normal position and control cylinder 674 during steering along the rows. Hydraulic connections are made from pump 148, line T50 with Tsv to the normally closed inlets of valves 708 and 709. Normally open exhausts of valves 708 and 709 are T d together to line T66, to T57, to T58, to tank 246. When .valve 7 08 is energized its piston is forced in opening passage from line T50 to line T68 to the inlet of a fourwaypilot-controlled spring returned valve .714 which connects when energized (as shown) to the bottom inlet port of valve 716 and to the bottom pilot port of valve 717. When valve 709 is energized it connects line T50 to line T69 to the inlet or" valve 714 which connects when energizedto the bottom pilot port of valve 716 and to the bottom inlet port of valve 717.

When the casters are turned 180 `degrees to make Aa return trip the .effects of cells 694 and 696 must be reversed, that is the direction of steering must be reversed both at the truck and at the bump rail. Accordingly reverse valve 714 is provided to reverse flow from valves 708 and 709 before admission to cylinder 674. The position of valve 714 is controlled by a caster position cam valve 720 normally exhausting, whichis opened to pressure b y a caster lug 96e. Valve720 is connected to pump 148 through line broken at b and to tank 246 through line broken at a. `In the engaged position shown valve 702 connects pressure line b to the cylinder of valve 714. Valve 720 has semicircular member 721 secured to the end of its spool rod whereby it is opened when lug 96e is turned thereagainst through more than degrees of the casters movement. Lug 96e is so positioned on the caster that the steering control is reversed as the casters pivot while indexing at the truck and returned during the reverse swivel at the bump rail. t

Light reaching cell 694 isampliied by 700 to operate valve 704 which then connects pressure to Valve 708; and accordingly valve `708r is opened `connecting pressure through reverse Valve 714 positioned to correspond with the position of the casters, through the lower inlet port of the selective check valve connected by valve 714, and

on to the required end of cylinder 674, thereby turning casters 664 so as to move the car upward on the drawing. Similarly llight reaching cell 696 indicates that the car is, too high on the sheet` and controls the opening of valve l709 sending pressure to the opposite end of cylinder 674 to steer the casters to lower the car on the sheet.

When the middle cell 695 receives the light it exhausts k the'pilot cylinders of both valves 708 yand 709 exhausting these valves, whereupon steering is not controlled'. Whenever light reaches cell 695 the indication is that the car isonthe beam. k

The car is` controlled to reverse its direction of movement when one-way jointed lever "724 on car 126e hits bump rail 626 opening three-way valve 726 normally held closed by spring 727 admitting fluid from pump 148 to the right-hand end of cylinder 674 through check valve 728 to move the piston of cylinder 674y to the opposite end, turning the casters approximately-180 degrees in a direction opposite to that taken for indexing whereby the rack is ready for another cycle of caster movement.

FIGUREZS shows the cycle of movement of the car representedk by a caster 664. The movement is limited by truck 630 and bump rail 626. Starting with position 1at the bump rail the wheel leads the caster pivot to position (2 as guided by light source 642 through action of the steering controls. When baille 650 blocks light 684 from reaching tube 680, cell 652 is energized by thislight, initiating the indexing of the truck; and the index controls Y of the car are ineffective, since they try toforce the casters to turn against the end of the piston travel causing the tiller to move down in FIGURE 24, causing light 642 to reach cell 694. When baffle 656 blocks light 685 from reaching tube 681 the casters are pivoted quickly (faster than the steering controls by adding restricting orifices 730 in lines T68 and T69 if necessary). The casters swivel clockwise until light 685 is blocked. If they have turned too much, past 90 degrees, light684 is soon blocked by baflle 65tl'iand the casters slowly returned .because of restriction 692 to about parallel with track 624. i The car is thus steered to keep the baille between the lamps 684 and 685. The truck is properly timed .so that it travels along with the car with' bale 656 always between arms 686 and 686. When the truckhas indexed the proper distanceY turn-limit-switch arm 612e opens switch 616e stopping the truck as switch 610e delayed by dashpot 613 closes( Since arm 612a-supplies current to switch 610e while opening the switch, there is no steady-state off position of the switch; and the truck is ready to index again when the dashpot 613 closes the switch, the dashpot being adjusted so that car 120e has time to leave the truck before the switch is closed. When cell 694 receives light from source 642, the casters having reached position 3 arer slowly pivoted in the direction shown but fast enough compared to the speed ofthe car to move the car in toward the Vtruck shielding light 685 dropping relay 687, energizing valve 691'to connectfluid to the left hand end of cylinder 674 (no line restriction) which pivots the casters quickly in the same direction. 'They casters cannot be pivoted too far because of the end-s of the cylinder travell which permit caster rotation of over 180 degreesv (about 200 degrees). As light 634 is blocked the casters slowly try to return as the car pulls away from the truck. The steering control valve 714 f was reversed during the later part of the last index swivel and the car is guided by light from source 642 to position 4 where the bump rail initiates the swivel indicated by the semicircle. The revolving of the casters then brings the car closer to the bump rail when swiveling fast v hits stop 186e.

tion of the casters.

Lever 724 can be. easily backed off the bump rail if it drops over it by pivoting at its joint under the backward force of the bump rail. l

'Lever switch 732 opens the ignition circuit when it As shown in FIGURE 25, a beam of light 626 from source S can be substituted for the fence or bump rail 626 as a stop. Accordingly valve 726 is operated by a solenoid 734 connected to a photo-electric cell 736 pref- `erably through an amplifier 73S. Photoelectric cell 736 is shielded and positioned on the tiller to intercept the kbeam from source S which is positionedV by the farmer to shine along the end of the area tobe tilled.

FIGURE 25 also shows a variation of the photoelectric steering controls for the tiller. Connection is made from pump 148m line T30 teeing to inlets of valves '7194' and 766 blocked in normal position but connected to outlet lines T82 and T83 respectively when the valves are in energizedposition` Lines T32 and T83 are connected through vfalve 795 in normal position respectively to lines T60 and T61 which are connected as in FIGURE 24 to operate cylinder 674. Valves 764 and 766 connect respectively lines T82 and T631v to lines T-ing to line T86, to tank 246. Valves 704', 765', and 766 are connected each in a usual electrical circuit to be controlled by photoelectric cells 694, 695, and 696 respectively. When light energizes cell 694, valve 764" is lifted, connecting fluid from pump 143 through valve .705 when cell 695 isv not energized to pressure the end of cylinder 674 to steer the tiller so that light will reach cell 695. When light energizes cell 696, valve 706' is lifted, connecting fluid from pump 148 through'valve 765 when cell 695 is not energized to pressure the opposite end of cylinder 674 and exhaust the other end. When light energiles cell 695, valve 795 is lifted to block the flow and hold the piston of cylinder 674 in position. Orifices 72'@ again can be provided to control the speed of steering.

The preferred arrangement for automatically operating the implement lifts and 170 pivotally secured to the bottom of car 120e is explained with aid of FIG- URES 26 and 28. The circular base of a wheel bracket on a caster 664 has a lobe 96 for actuating'four-way cam valves 239e and 230e' to control pressure to cylinders 174 and 174 respectively according to the swivel posi- The cam valves are positioned on Opposite sides of the swivel bracket so that valve 239e is actuated by lobe 96' when the vehicle is moving in the direction of thearrow in FIGURE 22 and so that valve 230e is actuated when the casters are reversed degrees, that is when Vthe vehicle is moving in the opposite direction. In the normaly position of valve 239e shown connection is from pump 148, line-T90, T-ing to inlet of valve 230eV to line T92, to the rod (lift) end of cylinder 174 whose'head is connected by line T93 to valve 236e, exhausting to line T94, to tank 246, lto hold implement 17 3 lifted as the tiller moves to the right. In the engaged position of valve 236eshown connection is from pump 148 to line T90, T-ing to theinlet of valve 239e to line T95, tothe head end of cylinder 174', whose rod end is connected by linie T96 to valve 236e', exhausting to line T94, to connect pressure to the lowering end of cylinder 174 to hold the plow or implement 178 in ground working position while the tiller moves to the right. When the tiller casters turn from right-angle movement or any other angle of tilling selected for operation between track 624 and stop 627 or 627 both implements are lifted. l

Referring to FIGURES 26 Yand 27, the caster swivel brackets have an upper hollow tube 754) which rests on spring 751 pocketed to vertically slide in tube 752 and to turn therewith. Through this tube extends shaft 5? to drive the caster'wheel preferably by beveled gear 63, secured to the bottom of shaft 59, engaging a beveled gear 754 formed as an integral part of the caster wheel concentric on one side thereof as shown. Shaft 59 is also splined to telescope on an upper hollowY tube, shaft l 50', on which is secured a drum or other drive means 49 for the caster wheel. Springs 751 improve the riding quality.

to turn together by chain 94 secured around thevsprockets thereon. Likewise the" rear swivel casters RC are connected together by chain 94 or other nonslip means.

Beveled gears 760 and 760 secured `to turn on the axis of and as an integral part of a front and a rear caster swivel respectively. Bevel gears 760 and 760 engage respectively beveled gears 762 and 762 on the same side thereof. Gears 762 and 762" are respectively connected by spur gears or other nonslip means 763 respectively to shafts 764 and 764', which shafts are aligned and supported in bearings to the frame of the tiller (either bridge 30 or car 120e for example). A two faced clutch 770 is splined for axial movement on shaft 764 and actuated by shift yoke and lever 772 to engage the frame of the tiller when the clutch is moved to the rear or to engage shaft 764, preferably through clutch 776 secured on 'shaft 764, when clutch 770 is moved to the front ofthe tiller.

A steering wheel 778 is connected by chain and sprocket or other suitable power transmission means '780 to turn shaft 764 to steer the vehicle manually. One oi" more pins and holes 774 in the faces of clutches 770.arid"776" are positioned to engage only when the front and rear wheels are aligned for forward operation of the vehicle. One or more pins and holes (including some of the same ones Y774) in the frame and in `clutch 770 are positioned to engage only when the rear wheels are aligned for for-` ward operation of the vehicle. A dial 784 turned with the steering wheel 77S indicates when the front wheels are straight for shifting from two wheel steering and vice versa. The ratio of the gearing between shafts 764V and 764 and each caster is equal Aso that casters turn substantially equally when turned. Gear 668 is now secured on shaft 764' for automatic steering only when the four- Wheel steering is engaged. f

Having thus described a few embodiments of my invention which can have many variations it is to be under-` stood that I do not wish to be limited to only variations shown and described herewith but I contemplate to cover in the appended claims all modifications and variations which fall within the true spirit and scope of my invention.`

. l claim as my invention:

1. An automatic tilling vehicle comprising a bridge,

swivel casters supporting each end of the bridge, a track on said bridge along the length thereof, an implement car on the track, a cable drive having an endless cable on said bridge for pulling said car back and forth across the bridge, clutch means on said car for holding either running side of said cable drive to cause thei cable to pull the car in either direction or permit the. car to` stop, a

lever for controlling said clutchmeans, said lever having a forward, reverse and neutral position, two linkage rails spaced apart running along the length of the bridge on opposite sides of an arm of said lever, parallel arms pivotally supporting said linkage rails to said bridge to enable movement of said rails toward and away from each other, means for moving and biasing said lever means toward either said linkage rail according to the direction of travel' the bridge, selective means to control said bridge to continue to-run,'row locators on said linkage rails for actuating said lever to stop said car intermediate the ends of said bridge while said bridge operates, means controlled by movement of'said bridge for separating said linkage rails to start said car so that said car can index to the next row locator, whereby the implement car can cover ground in a series of rows and then be set to cover the ground in a series of crossrows.

V2. An automatic tiller comprising a bridge, swivel wheel units supporting each end of the bridge, a track on said bridge along the `length thereof, an implement car on the track, a cable drive having an endless cable on said bridge for pulling said car back and forth across the bridge,

means on said bridge to separately propel said bridge and said cable, clutch means on said car for locking either running side of said cable to the car to pull the car in either direction or permit both sides of the cable to pass to `stop the car, reversible biasing means for engaging said clutch means with either side of said cable loop, means on each end of said bridge to move said clutch into neutral position to stop said car, means engaged by said car at an end of said bridge to propel said bridge at angles to its length while said car is at that end of the bridge, means engaged by movement of the bridge to reverse said biasing means to start said car in reverse, whereby said car is `given back and forth and indexing movement, and means for guiding the bridge.

` 3. A tractor which comprises in combination a frame,`

a pluralityof swivel casters supporting said frame, a motor for operating said tractor, power transmission means for connecting said motor to drive said casters for propelling said tractor, the wheels of 'said casters being aligned in the same direction for tilting, steering means connecting said casters to turn together, means for steering, `said casters being free to rotate over 180 degrees, means responsive to a light beam for controlling said last named means to steer the tractor toV follow said beam of energy,` an energy source for directing said beam to said light beam responsive means, means for positioning and moving said source to guide said tractor in parallel rows, means for automatically swiveling said casters after a predetermined travel of said tractor to reverse said tractor,

and means for reversing the steering control when the cas`r ters are reversed so that steering'is controlled for movementv in'both directions on the energy beam.

4. A tilling system which comprises in combination, a first vehicle, a second vehicle adapted to support earth Working implement means, guide means extending along the field for guiding said first vehicle, means carried by said first vehicle for guiding said second vehicle along a line at an angle with respect to the line of movement for said first vehicle, means for indexing said first vehicle a predetermined distance along the field, means carried by said second vehicle for substantially stopping the component of movement of said second vehicle which is in a direction at right angles to said guide means, means carried by said `rst vehicle for actuating said last mentioned means by movement of said second vehicle at an end of its travel at an angle to said guide means, means on said second vehicle for reversing the movement of said second vehicle, means to actuate said last mentioned means to reverse said vehicle at each end of travel of said second vehicle, and means controlled by movement of said first vehicle for delaying operation of said last mentioned means while said` rst vehicle is-indexing.

5. A 'system for automatic tilling which comprises in combination a first vehicle, a second vehicle adapted to support earth Working implement means, means for propelling each said` vehicle, first guide means extending along a field to guide said first vehicle along the field, second guide means including means carried by said first vehicle for guiding said second vehicle at an angle with respect to said first guide means along a path determined by the position of said first vehicle, third means on said second vehicle to reverse the movement of saidsecond vehicle, means for reversing the direction of said second vehicle after a predetermined travel away from said first vehicle, control means for stopping movement of said second vehicle at'a point along said angle of movementin the opposite direction of travel, means for indexing said rst and second vehicles together a predetermined distance parallel to said guide means after said second vehicle reaches the point whereat said control means substantially limitsv further movement of said'second vehicle along the angle, means actuated by movement of said first vehicle for stopping movement of said first and second vehicles parallel said guide means and for actuation of said third means to reverse movement of said second vehicle along said angle whereby said second vehicle covers an area with back and forth indexing movements over a predetermined path having as many i movements as desired, a first implement lift and a second implement lift on said second vehicle, a directional tilling implement connected oppositely to each implement lift to till in opposite directions with alternate implements,

acylinder for actuating each said'lift, a pressure source, i Y a reverse valve for connecting said source to the lift ends of either cylinder according to the position of said valve,

and means engaged by movement, of said second vehicle for reversing said valve at each end of travel ofsald secondV vehicle to lift alternate implements on successive runs of said second vehicle and for lowering alternate implements for alternateoperation depending on the direction of travel. i ,l

' 6. A tilling system including in combination, a track along one side of an areay to be tilled, a control trucky on said track, animplernent car including swivel casters `for .supporting said car on the ground, means for driving said casters to propel said car, steering means connecting the casters to swivel together through more than 90 degrees each side of a position parallel said track, guide means on said truck for providing a radiant beam to guide said car, and means on said car controlled by said beamvfor controlling said steering means according to the position of the car relative to the beam to keep the car on the beam, means` for reversing said car in each direction controlled by movement of said car, and means for indexing said truck controlled by movement of said car whereby said car runs back and forth and indexes to till parallel rows while the-wheels of said casters rotate in one direction. v

'7. In a tillng system a guide vehicle, means for moving said guide vehicle in indexing movements, a tillng vehicle, means for propelling said tilling vehicle, means for guiding said guide vehicle along one side of an area to be tilled, a source of light on said guide vehicle for directing a beam at an angle to the line of travel of said guide vehicle for guiding said tilling vehicle, steering means on said tillng vehicle and means for controlling said steering means to follow the light of said source, means to reverse the travel of said tillng vehicle after apredetermined travel from saidguide vehicle, and light controlled means for indexing said first and second vehicles together whereby said tilling vehicle continuously moves back and forth on said angle and indexes to cover the` area of ground.

8. On a tiller which turns back and forth over anarea to be tilled a first implement lift and a second implement lift on Ysaid tiller each including a cylinder, circuit means for pressuring said cylinders, a right-hand plow connected to be supported by said first lift and facing one direct-ion of movement of the tiller, a left-hand plow connected to be i supported by said second lift and facing the L opposite direction from said right-hand plan, a reverse valve connecting pressure `to the lifting endv of either said cylinders according to the position of the reverse valve, means con- Zd ternate plows for operation depending on the direction of travel.

9. In a tillng system in combination at leastthree rails widely and equally spaced apart and individually secured with respect to the ground, a bridge spanning adjacent rails, grooved wheels on said rails under each endy of said bridge and means swivelly supporting said bridge on said wheels, drive means for propelling said bridge through said wheels, crossover tracks at ends of said rails, said crossover tracks being a continuation of said rails and including switch means on said rails whereby said bridge as guided by said rails is moveable from one run to the adjacent run withv said wheels rotating in Vone direction, means including any implement lift for attaching an implementto till the ground, and means fto automatically actuate said lift to raise the implement to clear said rails as the bridge crosses from one run to. another.

10. In a combination as claimed in claim 9,'said crossover tracks having curves whichV turn the casters before Vthe implement reaches the crossover tracks, said means for actuating the implement lift being controlled by the swivel position of the casters, implement lift means and power means for operating said lift means, control means operated by the turning of said casters to control said power means to lift whenever said casters are substantially turned from the direction of tillng.

11. In combination on an automatic tillng system having an implement vehicle which moves back and forth over a field, two implement lifts on the vehicle each having a lift-cylinder, a reversing valve and fluid circuit means alternately connecting pressure to lift said cylinders wheref by one said cylinder at a time is pressured to lift and the other connected to exhaust to lower, means engaged at the ends of travel of said vehicle to reverse said reversing valve, check valves in said circuit means to block the exhausting of said cylinders, bypassing valvesl connected across said check valves, and means controlling said bypassing valves to open when the tiller is aligned for tillng whereby either cylinder can lower depending on the position of said reversing valve.

12. In the combinationl claimed in claimlll said bypassing valves beign dual-pilot-pressure controlled where- 1n pressures to one port thereof closes the valve irrespective of pressures to the other control ports thereof.

13. On a bridge tiller an'implement lift ycontrol for insuring that the implements are lifted while the tiller is turned from wide gauge and which comprises, a linkage rail extending along the length of the bridge, parallel linkage, arms pivotally supporting said linkage rail to said bridge in a parallelogram arrangement to enable movement of said rail to parallel positions, a cylinder cony nected to position said rail, an implementl car on said bridge, a valve on said car. controlled by said rail and connected to control the implement lift, and means for actuating said cylinder responsive to movement of said bridge from wide gage to narrow gage.

1d.l In combination, a first and a second object arrangedl forl guided and limited relative movement, a control linkage on said first object having a linkage rail along the dlrection in which the objects have relative guided movement'and means. for mounting said rail to said first object to move said rail to parallel positions thereon, a control lever for saidsecond object pivoted to said second object to rlde on said linkage rail as said second object moves ,along said first object, means to move said linkage rail in parallel positionsV for controlling said lever to control said second object.

i5. A tiller having in combination a bridge-like frame, a .truckv for supporting one end of said frame, said truck having a swivel with substantially vertical axis about which said frame can rotate, firstwheels for propelling and supporting said truck and wheels for supporting land trolled by movement of said tiller to reverse said valve propelling the other end of said frame, a shaft having its ax1s through and at right angles to the axis of said swivel, two rvdriven beveled gears Asecured to said shaft with the 

1. AN AUTOMATIC TILLING VEHICLE COMPRISING A BRIDGE, SWIVEL CASTERS SUPPORTING EACH END OF THE BRIDGE, A TRACK ON SAID BRIDGE ALONG THE LENGTH THEREOF, AN IMPLEMENT CAR ON THE TRACK, A CABLE DRIVE HAVING AN ENDLESS CABLE ON SAID BRIDGE FOR PULLING SAID CAR BACK AND FORTH ACROSS THE BRIDGE, CLUTCH MEANS ON SAID CAR FOR HOLDING EITHER RUNNING SIDE OF SAID CABLE DRIVE TO CAUSE THE CABLE TO PULL THE CAR IN EITHER DIRECTION OR PERMIT THE CAR TO STOP, A LEVER FOR CONTROLLING SAID CLUTCH MEANS, SAID LEVER HAVING A FORWARD, REVERSE AND NEUTRAL POSITION, TWO LINKAGE RAILS SPACED APART RUNNING ALONG THE LENGTH OF THE BRIDGE ON OPPOSITE SIDES OF AN ARM OF SAID LEVER, PARALLEL ARMS PIVOTALLY SUPPORTING SAID LINKAGE RAILS TO SAID BRIDGE TO ENABLE MOVEMENT OF SAID RAILS TOWARD AND AWAY FROM EACH OTHER, MEANS FOR MOVING AND BIASING SAID LEVER MEANS TOWARD EITHER SAID LINKAGE RAIL ACCORDING TO THE DIRECTION OF TRAVEL INTENDED FOR SAID CAR, MEANS ENGAGED BY SAID CAR AT AN END OF SAID BRIDGE OT PROPEL SAID B RIDGE AT AN ANGLE TO ITS LENGTH WHILE SAID CAR IS AT THAT END OF THE BRIDGE, MEANS ON EACH END OF THE BRIDGE TO THROW SAID LEVER INTO NEUTRAL TO STOP SAID CAR, MEANS ENGAGED BY MOVEMENT OF THE BRIDGE TO REVERSE SAID BIASING MEANS TO START SAID CAR IN REVERSE, MEANS TO GUIDE THE BRIDGE ALONG ITS ANGLE OF TRAVEL, MEANS AT ENDS OF TRAVEL FOR THE BRIDGE FOR REVERSING THE BRIDGE, SELECTIVE MEANS TO CONTROL SAID BRIDGE TO CONTINUE TO RUN, ROW LOCATORS ON SAID LINKAGE RAILS FOR ACTUATING SAID LEVER TO STOP SAID CAR INETERMEDIATE THE ENDS OF SAID BRIDGE WHILE SAID BRIDGE OPERATES, MEANS CONTROLLED BY MOVEMENT OF SAID BRIDGE FOR SEPARATING SAID LINKAGE RAILS TO START SAID CAR SO THAT SAID CAR CAN INDEX TO THE NEXT ROW LOCATOR, WHEREBY THE IMPLEMENT CAR CAN COVER GROUND IN A SERIES OF ROWS AND THEN BE SET TO COVER THE GROUND IN A SERIES OF CROSSROWS. 